Abstract MP30: Circulating Sars-cov-2 Spike Protein 1 Causes Microarteriolar Oxidative Stress, Endothelial Dysfunction And Enhanced Thromboxane And Endothelin Contractility That Are Prevented By Spironolactone.

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Dan Wang ◽  
Christopher S Wilcox
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
Fluorescence Microscopy ◽  
Vascular Dysfunction ◽  
Microvascular Complications ◽  
Spike Protein ◽  
Ros Generation ◽  
Intravenous Injections ◽  
Novel Model

Introduction and hypothesis: Following bodily entry, the SARS-CoV-2 virus undergoes pulmonary replication with release of circulating viral spike protein 1 (SP1) into the bloodstream. Uptake of SP1 by endothelial cells might provoke vascular dysfunction and thrombosis. We hypothesized that spironolactone could prevent microvascular complications from circulating SP1 in COVID-19. Methods: male C57Bl/6 mice received spironolactone (100 mg · kg -1 · d -1 PO x 3d) or vehicle and intravenous injections of recombinant full-length human SP1 (10 μg per mouse) or vehicle. They were euthanized after 3 days. Mesenteric resistant arterioles (n=4 per group) were dissected and mounted on isometric myographs. Acetylcholine-induced EDRF responses and L-NAME-inhibitable NO generation (DAF-FM fluorescence) were studied in pre-constricted vessels and contraction to endothelin 1 (ET1) or thromboxane (U-46, 619) and ET1-induced ROS (PEG-SOD inhibitable ethidium: dihydroethidium fluorescence) were studied by fluorescence microscopy in other vessels. Results: SP1 reduced acetylcholine-induced EDRF (17 ± 3 vs 27 ± 5 % mean ± sem; P < 0.05) and NO generation (0.21 ± 0.03 vs 0.36 ± 0.04, F 1 /F 0 ; P < 0.05) while increasing contraction to ET1 (10 -7 mol·l -1 : 124 ± 13 vs 89 ± 4 %; P < 0.05) and U-46, 619 (10 -6 mol·l -1 :114± 5 vs 87± 6 %; P < 0.05) and ET1-induced ROS generation(0.30± 0.08 vs 0.09± 0.03; P < 0.05). Spironolactone did not modify any of these responses in vessels from normal mice but prevented all the effects of SP1. Conclusion: these preliminary studies provide a novel model to study COVID-19 vasculopathy. They indicate that spironolactone can provide protection from microvascular oxidative stress, endothelial dysfunction and enhanced contractility and might thereby moderate COVID-19 complications.

scholarly journals Lipoic acid antagonizes paraquat-induced vascular endothelial dysfunction by suppressing mitochondrial reactive oxidative stress

2019 ◽  
Vol 8 (6) ◽  
pp. 918-927 ◽  
Author(s):  
Li Pang ◽  
Ping Deng ◽  
Yi-dan Liang ◽  
Jing-yu Qian ◽  
Li-Chuan Wu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
Lipoic Acid ◽  
Microvascular Endothelial Cells ◽  
Ros Generation ◽  
Protective Effects ◽  
Migration Ability ◽  
Microvascular Endothelial

Abstract Paraquat (PQ) is a widely used herbicide in the agricultural field. The lack of an effective antidote is the significant cause of high mortality in PQ poisoning. Here, we investigate the antagonistic effects of alpha lipoic acid (α-LA), a naturally existing antioxidant, on PQ toxicity in human microvascular endothelial cells (HMEC-1). All the doses of 250, 500 and 1000 μM α-LA significantly inhibited 1000 μM PQ-induced cytotoxicity in HMEC-1 cells. α-LA pretreatment remarkably diminished the damage to cell migration ability, recovered the declined levels of the vasodilator factor nitric oxide (NO), elevated the expression level of endothelial nitric oxide synthases (eNOS), and inhibited the upregulated expression of vasoconstrictor factor endothelin-1 (ET-1). Moreover, α-LA pretreatment inhibited reactive oxygen species (ROS) generation, suppressed the damage to the mitochondrial membrane potential (ΔΨm) and mitigated the inhibition of adenosine triphosphate (ATP) production in HMEC-1 cells. These results suggested that α-LA could alleviate PQ-induced endothelial dysfunction by suppressing oxidative stress. In summary, our present study provides novel insight into the protective effects and pharmacological potential of α-LA against PQ toxicity in microvascular endothelial cells.

scholarly journals Citrullination of histones decreases extracellular histones-mediated oxidative stress, cell death, and vascular dysfunction in endothelial cells

2021 ◽  
Vol 165 ◽  
pp. 35
Author(s):  
Rebeca Osca-Verdegal ◽  
Jesús Beltrán-García ◽  
Ana B. Paes ◽  
Elena Nacher-Sendra ◽  
Federico V. Pallardó ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Cell Death ◽  
Vascular Dysfunction ◽  
Extracellular Histones

scholarly journals High stretch induces endothelial dysfunction accompanied by oxidative stress and actin remodeling in human saphenous vein endothelial cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Girão-Silva ◽  
M. H. Fonseca-Alaniz ◽  
J. C. Ribeiro-Silva ◽  
J. Lee ◽  
N. P. Patil ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Endothelial Dysfunction ◽  
Saphenous Vein ◽  
Saphenous Vein Graft ◽  
Artery Bypass ◽  
Bypass Graft ◽  
Human Saphenous Vein ◽  
Actin Remodeling

AbstractThe rate of the remodeling of the arterialized saphenous vein conduit limits the outcomes of coronary artery bypass graft surgery (CABG), which may be influenced by endothelial dysfunction. We tested the hypothesis that high stretch (HS) induces human saphenous vein endothelial cell (hSVEC) dysfunction and examined candidate underlying mechanisms. Our results showed that in vitro HS reduces NO bioavailability, increases inflammatory adhesion molecule expression (E-selectin and VCAM1) and THP-1 cell adhesion. HS decreases F-actin in hSVECs, but not in human arterial endothelial cells, and is accompanied by G-actin and cofilin’s nuclear shuttling and increased reactive oxidative species (ROS). Pre-treatment with the broad-acting antioxidant N-acetylcysteine (NAC) supported this observation and diminished stretch-induced actin remodeling and inflammatory adhesive molecule expression. Altogether, we provide evidence that increased oxidative stress and actin cytoskeleton remodeling play a role in HS-induced saphenous vein endothelial cell dysfunction, which may contribute to predisposing saphenous vein graft to failure.

scholarly journals Kidney dysfunction in the low-birth weight murine adult: implications of oxidative stress

2018 ◽  
Vol 315 (3) ◽  
pp. F583-F594 ◽  
Author(s):  
Wasan Abdulmahdi ◽  
May M. Rabadi ◽  
Edson Jules ◽  
Yara Marghani ◽  
Noor Marji ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Birth Weight ◽  
Endothelial Dysfunction ◽  
Low Birth Weight ◽  
Vascular Dysfunction ◽  
Vascular Density ◽  
Immunofluorescence Analysis ◽  
Doppler Flowmetry ◽  
Maternal Undernutrition ◽  
Nephron Endowment

Maternal undernutrition (MUN) during pregnancy leads to low-birth weight (LBW) neonates that have a reduced kidney nephron endowment and higher morbidity as adults. Using a severe combined caloric and protein-restricted mouse model of MUN to generate LBW mice, we examined the progression of renal insufficiency in LBW adults. Through 6 mo of age, LBW males experienced greater albuminuria (ELISA analysis), a more rapid onset of glomerular hypertrophy, and a worse survival rate than LBW females. In contrast, both sexes experienced a comparable progressive decline in renal vascular density (immunofluorescence analysis), renal blood flow (Laser-Doppler flowmetry analysis), glomerular filtration rate (FITC-sinistrin clearance analysis), and a progressive increase in systemic blood pressure (measured via tail-cuff method). Isolated aortas from both LBW sexes demonstrated reduced vasodilation in response to ACh, indicative of reduced nitric oxide bioavailability and endothelial dysfunction. ELISA and immunofluorescence analysis revealed a significant increase of circulating reactive oxygen species and NADPH oxidase type 4 (NOX4) expression in both LBW sexes, although these increases were more pronounced in males. Although more effective in males, chronic tempol treatment did improve all observed pathologies in both sexes of LBW mice. Chronic NOX4 inhibition with GKT137831 was more effective than tempol in preventing pathologies in LBW males. In conclusion, despite some minor differences, LBW female and male adults have a reduced nephron endowment comparable with progressive renal and vascular dysfunction, which is associated with increased oxidative stress and subsequent endothelial dysfunction. Tempol treatment and/or NOX4 inhibition attenuates renal and vascular dysfunction in LBW adults.

Increased activity of mitochondrial uncoupling protein 2 improves stress resistance in cultured endothelial cells exposed in vitro to high glucose levels

2015 ◽  
Vol 309 (1) ◽  
pp. H147-H156 ◽  
Author(s):  
Agnieszka Koziel ◽  
Izabela Sobieraj ◽  
Wieslawa Jarmuszkiewicz
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Stress Resistance ◽  
High Glucose ◽  
Cultured Cells ◽  
Uncoupling Protein ◽  
Negative Regulator ◽  
Ros Generation ◽  
Mitochondrial Ros ◽  
Increased Activity

The endothelium is relatively independent of the mitochondrial energy supply, but mitochondria-derived ROS may play an important role in the development of many cardiovascular diseases. Energy-dissipating uncoupling proteins (UCPs) mediate free fatty acid-activated, purine nucleotide-inhibited proton conductance (uncoupling) in the inner mitochondrial membrane. We have described a functional characteristic and an antioxidative role for UCP2 in endothelial cells and isolated mitochondria and how this function is altered by long-term growth in high concentrations of glucose. Human umbilical vein endothelial cells (EA.hy926 line) were grown in media with either high (25 mM) or normal (5.5 mM) glucose concentrations. Under nonphosphorylating and phosphorylating conditions, UCP activity was significantly higher in mitochondria isolated from high glucose-treated cells. More pronounced control of the respiratory rate, membrane potential, and ROS by UCP2 was observed in these mitochondria. A greater UCP2-mediated decrease in ROS generation indicates an improved antioxidative role for UCP2 under high glucose conditions. Mitochondrial and nonmitochondrial ROS generations were significantly higher in high glucose-treated cells independent of UCP2 expression. UCP2 gene silencing led to elevated mitochondrial ROS formation and ICAM1 expression, especially in high glucose-cultured cells. UCP2 influenced endothelial cell viability and resistance to oxidative stress. Endothelial cells exposed to high glucose concentrations were significantly more resistant to peroxide. In these cells, the increased activity of UCP2 led to improved stress resistance and protection against acute oxidative stress. Our results indicate that endothelial UCP2 may function as a sensor and negative regulator of mitochondrial ROS production in response to hyperglycemia.

EGCG protects against oxidized LDL-induced endothelial dysfunction by inhibiting LOX-1-mediated signaling

2010 ◽  
Vol 108 (6) ◽  
pp. 1745-1756 ◽  
Author(s):  
Hsiu-Chung Ou ◽  
Tuzz-Ying Song ◽  
Yueh-Chiao Yeh ◽  
Chih-Yang Huang ◽  
Shun-Fa Yang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
Nadph Oxidase ◽  
P38 Mapk ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Ros Generation ◽  
Low Density ◽  
Oxidized Low Density Lipoprotein ◽  
Amino Terminal

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), originally identified as the major receptor for oxidized low-density lipoprotein (oxLDL) in endothelial cells, plays a major role in the pathology of vascular diseases. Green tea consumption is associated with reduced cardiovascular mortality in some epidemiological studies. In the present study, we hypothesized that the most abundant polyphenolic compound in tea, epigallocatechin-3-gallate (EGCG), can downregulate parameters of endothelial dysfunction by modulating LOX-1-regulated cell signaling. In cultured human umbilical vein endothelial cells (HUVECs), exposure to oxLDL (130 μg/ml), which led to an increase in LOX-1 expression at the RNA and protein levels, was abrogated by addition of EGCG or DPI, a well-known inhibitor of flavoproteins, suggesting the involvement of NADPH oxidase. Furthermore, oxLDL rapidly activated the membrane translocation of Rac-1 and p47phox and the subsequent induction of ROS generation, which was suppressed markedly by pretreatment with EGCG or anti-LOX-1 monoclonal antibody. OxLDL also increased p38 MAPK phosphorylation and decreased phosphorylation of the amino-terminal region of Akt, with maximal induction at about 30 min, and NF-κB phosphorylation within 1 h, resulting in redox-sensitive signaling. In addition, oxLDL diminished the expression of endothelial nitric oxide synthase (eNOS), enhanced the expression of endothelin-1 and adhesion molecules (ICAM, E-selectin, and monocyte chemoattractant protein-1), and increased the adherence of monocytic THP-1 cells to HUVECs. Pretreatment with EGCG, however, exerted significant cytoprotective effects in all events. These data suggest that EGCG inhibits the oxLDL-induced LOX-1-mediated signaling pathway, at least in part, by inhibiting NADPH oxidase and consequent ROS-enhanced LOX-1 expression, which contributes to further ROS generation and the subsequent activation of NF-κB via the p38 MAPK pathway. Results from this study may provide insight into a possible molecular mechanism by which EGCG suppresses oxLDL-mediated vascular endothelial dysfunction.

The role of cholesteryl ester transfer protein expression on endothelial cells: oxidative stress and vascular dysfunction

2017 ◽  
Vol 108 ◽  
pp. S96
Author(s):  
Amarylis Claudine Bonito Wanschel ◽  
Estela Lorza-Gil ◽  
Alessandro G. Salerno ◽  
Adriene A. Paiva ◽  
Jeferson Stravinsky ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Protein Expression ◽  
Cholesteryl Ester ◽  
Cholesteryl Ester Transfer Protein ◽  
Vascular Dysfunction ◽  
Transfer Protein

scholarly journals Inhibitory Effect of a French Maritime Pine Bark Extract-Based Nutritional Supplement on TNF-α-Induced Inflammation and Oxidative Stress in Human Coronary Artery Endothelial Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Kristine C. Y. McGrath ◽  
Xiao-Hong Li ◽  
Lucinda S. McRobb ◽  
Alison K. Heather
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Cell Adhesion ◽  
Coronary Artery ◽  
Endothelial Dysfunction ◽  
Cell Adhesion Molecule ◽  
Bark Extract ◽  
Human Coronary Artery ◽  
Cell Adhesion Molecule 1 ◽  
And Oxidative Stress

Oxidative stress and inflammation, leading to endothelial dysfunction, contribute to the pathogenesis of atherosclerosis. The popularity of natural product supplements has increased in recent years, especially those with purported anti-inflammatory and/or antioxidant effects. The efficacy and mechanism of many of these products are not yet well understood. In this study, we tested the antioxidant and anti-inflammatory effects of a supplement, HIPER Health Supplement (HIPER), on cytokine-induced inflammation and oxidative stress in human coronary artery endothelial cells (HCAECs). HIPER is a mixture of French maritime pine bark extract (PBE), honey, aloe vera, and papaya extract. Treatment for 24 hours with HIPER reduced TNF-α-induced reactive oxygen species (ROS) generation that was associated with decreased NADPH oxidase 4 and increased superoxide dismutase-1 expression. HIPER inhibited TNF-αinduced monocyte adhesion to HCAECs that was in keeping with decreased expression of vascular cell adhesion molecule-1 and intercellular cell adhesion molecule-1 and decreased nuclear factor-kappa B (NF-κB) activation. Further investigation of mechanism showed HIPER reduced TNF-αinduced IκBαand p38 and MEK1/2 MAP kinases phosphorylation. Our findings show that HIPER has potent inhibitory effects on HCAECs inflammatory and oxidative stress responses that may protect against endothelial dysfunction that underlies early atherosclerotic lesion formation.

scholarly journals Lysophosphatidylcholine induces oxidative stress in  human endothelial cells via NOX5 activation - implications in atherosclerosis

2021 ◽  
Author(s):  
Josiane Fernandes da Silva ◽  
Juliano V Alves ◽  
Julio A Silva-Neto ◽  
Rafael Menezes Costa ◽  
Karla Bianca Neves ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Intracellular Calcium ◽  
Calcium Influx ◽  
Ros Generation ◽  
Ros Production ◽  
Aortic Endothelial Cells ◽  
Cell Dysfunction ◽  
Inflammatory Processes ◽  
Electron Paramagnetic Spectroscopy

Objective: The mechanisms involved in NOX5 activation in atherosclerotic processes are not completely understood.  This study tested the hypothesis that lysophosphatidylcholine (LPC), a proatherogenic component of oxLDL, induces endothelial calcium influx, which drives NOX5-dependent reactive oxygen species (ROS) production, oxidative stress, and endothelial cell dysfunction.  Approach: Human aortic endothelial cells (HAEC) were stimulated with LPC (10-5 M, for different time points).  Pharmacological inhibition of NOX5 (Melittin, 10-7 M) and NOX5 gene silencing (siRNA) were used to determine the role of NOX5-dependent ROS production in endothelial oxidative stress induced by LPC.  ROS production was determined by lucigenin assay and electron paramagnetic spectroscopy (EPR), calcium transients by Fluo4 fluorimetry, and NOX5 activity and protein expression by pharmacological assays and immunoblotting, respectively. Results: LPC increased ROS generation in endothelial cells at short (15 min) and long (4 h) stimulation times.  LPC-induced ROS was abolished by a selective NOX5 inhibitor and by NOX5 siRNA. NOX1/4 dual inhibition and selective NOX1 inhibition only decreased ROS generation at 4 h.  LPC increased HAEC intracellular calcium, important for NOX5 activation, and this was blocked by nifedipine and thapsigargin.  Bapta-AM, selective Ca2+ chelator, prevented LPC-induced ROS production.  NOX5 knockdown decreased LPC-induced ICAM-1 mRNA expression and monocyte adhesion to endothelial cells. Conclusion: These results suggest that NOX5, by mechanisms linked to increased intracellular calcium, is key to early LPC-induced endothelial oxidative stress and pro-inflammatory processes.  Since these are essential events in the formation and progression of atherosclerotic lesions, this study highlights an important role for NOX5 in atherosclerosis.

scholarly journals NADPH Oxidase Activation and Endothelial Nitric Oxide Synthase Uncoupling Contribute to Endothelial Dysfunction in Antiphospholipid Syndrome

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4639-4639
Author(s):  
Meifang Wu ◽  
Suman Kundu ◽  
Keith R. McCrae
Keyword(s):  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
Nadph Oxidase ◽  
Board Of Directors ◽  
Conditioned Medium ◽  
Antiphospholipid Syndrome ◽  
Ros Generation ◽  
Advisory Committees ◽  
Nitrative Stress ◽  
Enos Uncoupling

Abstract Introduction: Antiphospholipid syndrome (APS) is characterized by thrombosis and/or recurrent fetal loss in the presence of persistently elevated antiphospholipid antibodies (APLA). The majority of pathologic APLA are directed against β2-glycoprotein I (β2GPI). APLA cause endothelial dysfunction, though the underlying mechanisms have not been clearly delineated. Methods: Endothelial cells (EC) were incubated with β2GPI and either control antibodies or anti-β2GPI antibodies affinity-purified from sera of patients with APS, in the absence or presence of diapocynin, an NADPH oxidase (NOX) inhibitor, or siRNA against NOX1, NOX2, or NOX4. Generation of reactive oxygen species (ROS) in EC and conditioned medium were measured using fluorescent dyes (CM-H2DCFDA and CellROX Deep Red) or chemiluminescent substrate. NOX1, NOX2, NOX4, 3-nitrotyrosine, and thioredoxin reductase 1 (TrxR1) expression were analyzed by western blot. eNOS monomer and dimer were detected using cold (4°C) SDS-PAGE and immunoblot. Immunoprecipitation of TrxR1 was performed using protein A/G agarose. EC activation was assessed by measuring expression of E-selectin. Results: Incubation of EC with β2GPI and anti-β2GPI antibodies stimulated ROS generation in EC, as well as the release of ROS into conditioned medium. Expression of NOX2, but not NOX1 or NOX4, was significantly increased in EC exposed to anti-β2GPI antibodies, but not control IgG. Preteatment of endothelial cells with diapocynin, a NOX inhibitor, or siRNA against NOX2 and NOX4, but not NOX1, inhibited endothelial cell activation by anti-β2GPI antibodies. Furthermore, anti-β2GPI antibody-treated EC generated more peroxynitrite, as determined by 3-nitrotyrosine expression. Treatment of EC with anti-β2GPI antibodies increased eNOS monomer/dimer ratio, suggesting eNOS uncoupling. Compared to control human IgG, the TrxR1 immunoprecipitate from EC treated with β2GPI and anti-β2GPI antibodies contained more 3-nitrotyrosine level, suggesting TrxR1 tyrosine residue modification by nitration and possible loss of function. Conclusions: β2GPI and anti-β2GPI antibodies stimulate ROS generation in EC, with release into the conditioned medium. The impairment of EC activation by diapocynin, NOX2 siRNA, or NOX4 siRNA suggests that NOX mediate EC activation by anti-β2GPI antibodies. Anti-β2GPI antibodies induce nitrative stress in EC, which might be explained by eNOS uncoupling induced by these antibodies. The nitration of TrxR1, an enzyme that prevents eNOS uncoupling, may result in the inactivation of TrxR1 and contribute to eNOS uncoupling. Taken together, these studies provide preliminary evidence of the contribution of NOX activation and eNOS uncoupling in mediating oxidative and nitrative stress and induction of EC dysfunction by APLA. Disclosures McCrae: Janssen: Membership on an entity's Board of Directors or advisory committees; Syntimmune: Consultancy; Momenta: Consultancy; Halozyme: Membership on an entity's Board of Directors or advisory committees.

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